Download i. Genetics

Genetics
New Learning Goal:

To describe how genetics are passed
from one generation to another.
Fun Facts….

1. Monkeys and Humans have 98.8%of the same
DNA.

2. Humans have 50% of the same DNA as
bananas.

3. You get 99.9% of your DNA from your
parents.
Let’s let my buddy, Bill Nye
introduce us to Genetics….

http://www.youtube.com/watch?v=OZIQTMHmWmg
Gregor Mendel
(1822-1884)
The Father of
Genetics
copyright cmassengale
5
Gregor Johann Mendel
Austrian
monk
Studied the
inheritance of traits in
pea plants
Developed the laws of
inheritance
Mendel's work was not
recognized until the
turn of the 20th
century
6
Gregor Johann Mendel
Between
1856 and
1863, Mendel
cultivated and
tested thousands of
pea plants
He
found that the
plants' offspring
retained traits of the
parents
copyright cmassengale
7
Particulate Inheritance
Mendel
stated that
physical traits are
inherited as “particles”
Mendel did not know
that the “particles”
were actually
Chromosomes & DNA
copyright cmassengale
8
I. What is genetics?
i. Genetics
The study of _______
(how traits are
passed from parents
to offspring)
I. What is genetics?
i. Genetics
The study of heredity
(how traits are
passed from parents
to offspring)
ii. Heredity
How an organism passes ____
from one generation to the
next.
ii. Heredity
How an organism passes traits
from one generation to the
next.
iii. Trait
A __________ or
quality of an
organism
iii. Trait
A characteristic or
quality of an
organism
v. Variability
The differences between
________ in a given population
v. Variability
The differences between
organisms in a given population
vi. Adaptation
A structure or
behavior that
allows an organism
to survive in its
environment.
sidewinder article
Exit Ticket
1.
Who is the father of Genetics?
2.
What is heredity?
3.
What is a trait?
4.
Describe adaptation that we saw with the
snakes.
1
New Learning Goal:

To describe how genetics are passed
from one generation to another.
BrainPop Time….
http://www.brainpop.com/health/geneticsgrowtha
nddevelopment/dna/
DNA
DNA stands for deoxyribonucleic acid
This chemical substance is present in the nucleus
of all cells in all living organisms
The kind of cell which is formed, (muscle, blood,
nerve etc.) is controlled by DNA
The kind of organism which is produced (giraffe, herring,
human, etc.) is controlled by DNA
2
Ribose &
deoxyribose
Ribose is a sugar, like glucose, but with only five
Oxygen atoms in its molecule
Deoxyribose is almost the same but lacks one
oxygen atom
Both molecules may be represented by the symbol
4
5
The bases
The most common organic bases are
Adenine
Thymine
Cytosine
Guanine
(A)
(T)
(C)
(G)
6
Nucleotides
The deoxyribose,
the phosphate,
and one of the bases
Combine to form a nucleotide
PO4
adenine
deoxyribose
Joined nucleotides
7
PO4
PO4
PO4
PO4
A molecule of
DNA is formed
by millions of
nucleotides
joined together
in a long chain
8
In fact, the DNA usually consists of a double
strand of nucleotides
The sugar-phosphate chains are on the
outside
and the strands are held together by chemical
bonds between the bases
2-stranded DNA
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
9
10
Bonding
The bases always pair up in the same way
Adenine forms a bond with Thymine
Adenine
Thymine
and Cytosine bonds with Guanine
Cytosine
Guanine
Bonding continued
11
PO4
PO4
adenine
thymine
PO4
PO4
cytosine
guanine
PO4
PO4
PO4
PO4
Pairing up
PO4
12
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
PO4
13
The paired strands are coiled into a spiral called
A DOUBLE HELIX
14
THE DOUBLE
HELIX
bases
sugar-phosphate
chain
15
A model of
part of a DNA
molecule
Build a DNA molecule – you try it!
Your Exit Tickets will be
Passed Out Now 
CHROMOSOMES
New Learning Goal:

To describe how genetics are
passed from one generation to
another.
Numbers of
chromosomes
 Constant
for each cell in the
body.
 Constant
throughout the life of
an individual (you don’t lose or
gain chromosomes)
 Constant
species
© 2007 Paul Billiet ODWS
for all members of a
Organism
Human
Chromosome
numbers
46
Chimpanzee
48
House Mouse
40
Maize
20
© 2007 Paul Billiet ODWS
Human chromosomes
Identifying chromosomes
Chromosomes can be
identified by:

Their size

Their shape and flexiblity

Banding patterns
Chromosomes are analyzed by
organising them into a
KARYOTYPE
© 2007 Paul Billiet ODWS
Female
Male
The inheritance of gender
Mother
Father
XX
XY
X
X
X
X
Y
X
XX
XY
X
XX
XY
Y
Possible
children
Chance of a girl 50%
Chance of a boy 50%
Exit Ticket:
On the back of your notes,
create a Punnett Square for
Blue Eyes and Brown Eyes.
Dominant and
Recessive Traits
New Learning Goal:

To describe how genetics are
passed from one generation to
another.
Before we begin, let’s take a
look at a quick video….

http://www.youtube.com/watch?v=Mehz7tCxjSE
What are traits?


Physical Traits
 Can
be seen by others
 Eye
color, hair color, height, left handed
Acquired Traits
 Learned
skills
 Playing
a sport, riding a bike, playing a musical
instrument

Behavioral Traits
 Instinctual
 Nest
actions
building and migration
Terms Used in
Modern Genetics

Genotype
 The
particular alleles (genes) an individual carries
 They
are inherited from your biological parents
 Genes

control your traits
Phenotype
 An
individual’s observable traits
 What
people can SEE when they look at you
Terms Used in
Modern Genetics

An individual with non-identical alleles of
a gene is heterozygous for that gene
 Examples:

Two or more
alternative forms of a
gene.
Bb, Tt, Aa
An individual with identical alleles of a
gene is homozygous for that gene
 Examples:
BB or bb, TT or tt
Terms Used in Modern
Genetics

An allele is dominant if its effect masks
the effect of a recessive allele paired
with it
 Capital
letters (A) signify dominant
alleles; lowercase letters (a) signify
recessive alleles
 Homozygous
dominant (AA)
 Homozygous
recessive (aa)
 Heterozygous
(Aa)
What traits do you have?

We will go through the most common
traits that people have

On your sheet, record if you have the
mentioned trait or not

You may have to ask your neighbor for
help 
Detached (EE, Ee) or
attached (ee) Earlobes
Can Tongue Roll (TT, Tt) or
Can’t (tt)
Dimples (DD, Dd) No Dimples
(dd)
Right (RR, Rr) or Left (rr)
handed?
Freckles (FF, Ff) No Freckles
(ff)
Curly (HH, Hh) or Straight
(hh)
Cleft Chin (CC, Cc) or No
Cleft (cc)
Allergies (AA, Aa) or No
Allergies (aa)
Normal (BB, Bb) Color Blindness (bb)
Can you see the
number inside
the circle?
If you cannot,
you may be
colorblind
Widow’s Peak (WW, Ww)
or Straight (ww)
Data
 Please
compare your results
(the chart) with 5 other
students.
 Does
our data support which
genes are dominant and which
genes are recessive?